Fix #137481

Find the length of the longest day name in the current locale. Use that length, rather than a constant "9", to decide if the names should be abbreviated.

Author: snoyes

Lib/calendar.py

@@ -370,7 +370,7 @@ def formatweekday(self, day, width):
         """
         Returns a formatted week day name.
         """
-        if width >= 9:
+        if width >= max(map(len, day_name)):
             names = day_name
         else:
             names = day_abbr